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Add trivial identities for &&, <>->, []-> and Boolean arguments.

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* src/ltlast/binop.cc (EConcat, UConcat): Rewrite "{b}<>-> f"
as "b && f", and rewrite "{b}[]->f" as "b->f".
* src/ltlast/binop.hh (binop::instance): Document trivial
identities for <>-> and []->.
* src/ltlast/multop.cc (multop::instance): Rewrite "b1 & b2"
as "b1 && b2" when b1 and b2 are Boolean.
(multop::multop): Always disable is.boolean for AndNLM.
* src/ltlast/multop.hh: Document the rewriting.
* src/ltltest/equals.cc: Show the two formulas if the exit_code
is 1, to help debugging.
* src/ltltest/equals.test: Add more tests.
* src/ltltest/kind.test: Adjust tests.
This commit is contained in:
Alexandre Duret-Lutz 2011-02-23 15:11:44 +01:00
parent 0e4e2a79b2
commit a2da5184b5
7 changed files with 63 additions and 13 deletions
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34
src/ltlast/multop.cc
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@ -45,18 +45,18 @@ namespace spot
{
case Concat:
case Fusion:
case AndNLM:
// Note: AndNLM(p1,p2) is a Boolean formula, but it is
// actually rewritten as And(p1,p2) by trivial identities
// before this constructor is called. So at this point,
// AndNLM is always used with at most one Boolean argument,
// and the result is therefore NOT Boolean.
is.boolean = false;
is.ltl_formula = false;
is.eltl_formula = false;
is.psl_formula = false;
is.eventual = false;
is.universal = false;
// fall through
case AndNLM:
// The non-matching-length-And (&) can only appear in the
// rational parts of PSL formula. We don't remove the
// Boolean flag, because applied to atomic propositions a&b
// has the same effect as a&&b.
case And:
for (unsigned i = 1; i < s; ++i)
props &= (*v)[i]->get_props();
@ -229,6 +229,27 @@ namespace spot
abs = constant::false_instance();
abs2 = 0;
weak_abs = 0;
// Make a first pass to gather all boolean terms.
{
vec* b = new vec;
vec::iterator i = v->begin();
while (i != v->end())
{
if ((*i)->is_boolean())
{
b->push_back(*i);
i = v->erase(i);
}
else
{
++i;
}
}
// - AndNLM(Exps1...,Bool1,Exps2...,Bool2,Exp3...) =
// AndNLM(Exps1...,Exps2...,Exp3...,And(Bool1,Bool2))
v->push_back(instance(And, b));
}
break;
case Or:
neutral = constant::false_instance();
@ -291,6 +312,7 @@ namespace spot
++i;
}
}
// We have a* & [*0] & c = 0
// and a* & [*0] & c* = [*0]
// So if [*0] has been seen, check if alls term recognize the